<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script >
    // 弹窗外部脚本
    alert('hello world');
</script>
<!--    外部脚本-->
<script src="dome1.js"></script>
</body>
</html>